You've ticked off the Tate Modern, lingered in the Louvre and marveled at the Met. But now you're in the mood for an out-of-the-ordinary museum experience far from the madding crowds. What's an art aficionado to do?

Simple: Skip the marquee museums—with their long lines and dawdling tour groups—and seek out some of the world's most fabulous privately owned art museums.

There are such gem-like collections in every corner of the globe. Some are hiding in plain sight, in well-known capital cities, while others are sequestered away in remote settings that require a sense of adventure—or, at least, a reliable GPS—to find. And some, like pop star George Michael's Goss-Michael Foundation in Dallas, are the culmination of a collector's particular obsession (in this case, contemporary British art), while others, like the famed Barnes Foundation in Philadelphia, span a range of eras and genres. Places like the Salvador Dalí Museum in the Surrealist master's hometown of Figueres, Spain, offer a comprehensive paean to a single artist.

Along with the chance to appreciate world-class art collections, private museums also afford visitors the rare opportunity to take a peek into the lives and passions of some of the world's wealthiest and most powerful people. Several of the museums on our list are the actual former homes of their patrons (and who doesn't love poking around in someone else's house, especially when their taste is as exquisite as Peggy Guggenheim's?).

Best of all, since many private museums are personal projects rather than crowd-pleasers, you'll likely get to explore them in relative quiet. A whirlwind tour can feel like a private art-appreciation odyssey.

Peggy Guggenheim Collection, Venice, Italy

If you don't normally associate the word "romantic" with museums, that's because you haven't gotten around to visiting the utterly transporting Palazzo Venier dei Leoni. Set right on Venice's Grand Canal, the palace, with its classical triple-arched façade decorated with stone lion's heads, is the former home of lifelong gallerist, art patron and collector Peggy Guggenheim.

Among the many artists whose work she championed—and collected—are some who became known as luminaries of the 20th century: Georges Braque, Piet Mondrian, Robert Motherwell and Jackson Pollock. Along with Peggy's vast personal collection, the museum houses works bestowed by the Solomon R. Guggenheim Foundation and a charming alfresco sculpture garden. guggenheim-venice.it

Barnes Foundation, Philadelphia

Courtesy The Barnes Foundation, Merion, Pennsylvania

Like many of the visionary museum founders on our list, Albert C. Barnes was a man ahead of his time. Between 1912 and 1951, this wealthy pharmaceutical-company owner gathered what is still considered one of the world's finest collections of Impressionist, post-Impressionist, and early Modern paintings (many by artists who were considered scandalous at the time).

Thanks to his keen eye, the collection includes a dazzling array of works by Cézanne, Picasso, Matisse, Renoir and van Gogh. One of the foundation's greatest treasures: the triptych of Matisse's dancers specially created in 1933 for the main gallery space above the Palladian windows in Merion, just outside Philadelphia. barnesfoundation.org

Beyeler Museum, Basel, Switzerland

Mark Niedermann / Courtesy Beyeler Museum

When renowned Swiss art dealer Ernst Beyeler and his wife, Hildy, were looking to house their formidable art collection, they found that no existing public museum—even in art-centric Basel—met their exacting standards. So, in 1997, they created their own.

The result is a work of art itself: a strikingly modern, single-level Renzo Piano building set amid formal gardens and designed to capture the interplay of light throughout the day—a fitting home for Monet's infamous Water Lilies series. Impressed yet? The Beyelers' collection, amassed over half a century, includes equally stunning works from the likes of Warhol, van Gogh, Picasso and Bacon. fondationbeyeler.ch/en

The Dalí Theatre-Museum, Figueres, Spain

Courtesy Fundació Gala-Salvador Dalí, Figueres, 2012

Salvador Dalí was certainly a trip, and it's worth making one of your own to check out the Surrealist master's work in situ. Set in Dalí's Catalonian hometown of Figueres, the Dalí Theatre-Museum was established by the artist himself on the remains of a 19th-century theater (which had been mostly destroyed by a fire in the Spanish Civil War).

As you'd expect, everything here is larger than life, heavily infused with whimsy, from the famous Mae West room, which pays homage to the silver-screen vamp, to the 1940s Cadillac in the courtyard that rains on the inside. Among the stunningly prolific artist's many famous works that deck the halls, you'll find endless homages to his wife and lifelong muse, Gala. salvador-dali.org

Goss-Michael Foundation, Dallas, Texas

Courtesy The Goss-Michael Foundation

We'll wager that most people who can sing along to the 1980s hit "Wake Me Up Before You Go-Go" have no idea that the pop star behind it is an avid art enthusiast. But it's true; along with the collaboration of longtime partner Kenny Goss, singer George Michael has created one of the Southwest's most fascinating and well-regarded museums.

Their collection is devoted exclusively to contemporary British artists, and its 500 works name-check all the hottest YBAs (Young British Artists)—including Tracey Emin, Gilbert & George and Damien Hirst. gossmichaelfoundation.org

Hess Collection, Napa, California

Winemaking isn't the only notable art in the Napa Valley, thanks to this outstanding private museum tucked away at the tranquil Hess winery. Founder Donald Hess has spent four decades amassing a collection that would be the envy of many big-city museums; his focus is narrow but deep, encompassing a catalog of time-spanning works from just a few artists.

The result is an intensive experience, with each exhibit room offering full immersion of a single artist. One of the most arresting displays is that of painter Franz Gertsch, whose gargantuan photo-realistic portraits call to mind the 17th-century Dutch masters. Works by Francis Bacon and Robert Motherwell are also showcased. hesscollection.com

MALBA, Buenos Aires, Argentina

Courtesy of MALBA

As if you needed another reason to hit up South America's most happening city, MALBA—officially known as the Museo de Arte Latinoamericano de Buenos Aires—offers a fantastic primer on 20th-century Latin American art.

The Costantini Foundation, the museum's permanent collection, includes towering figures of the Latin American art world, such as Diego Rivera, Antonio Berni and Frida Kahlo, while the temporary exhibits—like the current one, "Bye Bye American Pie," featuring works from artists like Nan Goldin, Larry Clark and Jean-Michel Basquiat—take a more global view. The museum also hosts screenings of landmark films, like Fritz Lang's Metropolis. malba.org.ar

Mathaf, Doha, Qatar

Mathaf: Arab Museum of Modern Art

An extended love letter to the artistic greats of the Arab World, this museum of modern Arab art is housed in a futuristic glass-and-steel building designed by French architect Jean-François Bodin. Founded by Sheikh Hassan bin Mohamed bin Ali Al Thani—one of the world's top art collectors—the museum displays works ranging from the 1800s to the present, from Southeast Asia to the Middle East.

While most of the collection centers on well-known Arabian artists, like Iraqi painter Dia Azzawi, the museum's purview also extends to artists exploring themes of Arab identity and Qatar's relationship with other countries. mathaf.org.qa

Miho Museum, Shiga, Japan

Designed by legendary architect I.M. Pei in 1966, this rural museum—a joint Japanese and American project—has a peerless mountainside setting in a nature preserve outside of Kyoto. The award-winning building is a showstopper itself: Fashioned from Magny Doré limestone, with much of the building set underground, the construction has sloping glass roofs that allow light to filter beautifully over the artworks displayed inside.

The collection is largely centered on priceless antiquities, which range from a towering Pakistani Buddha (circa A.D. 2nd century) to an Egyptian statue depicting Queen Arsinoe II, wife of Ptolemy (from 270-246 B.C.), along with ancient pottery and delicate Japanese glassware. miho.or.jp

MONA, Hobart, Australia

Most art enthusiasts had trouble locating the diminutive Australian state of Tasmania on a map—until gambling tycoon David Walsh came along in 2011 with his daring Museum of Old and New Art, or MONA. Walsh, a high-flying provocateur, named his first show "Monanism" and has described the museum as "a subversive adult Disneyland"—a promise born out of the array of exhibits concerned with explicit matters of sex and death.

The building is comprised of a series of subterranean galleries carved out of a sandstone riverbank cliff; visitors descend via a glass elevator. Along with Walsh's private collection, which includes iconic works such as painter Sidney Nolan's "Snake," expect to be provoked/entertained/disturbed/offended by works like the groundbreaking "Cloaca Machine," by Wim Delvoye, an intricate apparatus that mimics the human digestive system. mona.net.au